WARNING: kernel/sched/fair.c:3275 update_blocked_averages+0x628/0x660

[Naresh Kamboju]

[Please ignore if it already reported]

Regression found,
The following kernel warning reported on Linux next 20210621 while booting
arm64 Juno-r2 device. And also noticed a similar crash on an x86_64 machine.

Crash log:
-----------------
[   29.244230] ------------[ cut here ]------------
[   29.248861] cfs_rq->avg.load_avg || cfs_rq->avg.util_avg ||
cfs_rq->avg.runnable_avg
[   29.248874] WARNING: CPU: 1 PID: 156 at kernel/sched/fair.c:3275
update_blocked_averages+0x628/0x660
[   29.265784] Modules linked in: fuse
[   29.269282] CPU: 1 PID: 156 Comm: kworker/u12:2 Not tainted
5.13.0-rc7-next-20210621 #1
[   29.277305] Hardware name: ARM Juno development board (r2) (DT)
[   29.283241] Workqueue:  0x0 (rpciod)
[   29.286828] pstate: 600000c5 (nZCv daIF -PAN -UAO -TCO BTYPE=--)
[   29.292844] pc : update_blocked_averages+0x628/0x660
[   29.297817] lr : update_blocked_averages+0x628/0x660
[   29.302788] sp : ffff8000133fbb60
[   29.306103] x29: ffff8000133fbb60 x28: ffff00097ef382c0 x27: ffff00080090ca00
[   29.313264] x26: 00000006cacd5228 x25: 0000000000000000 x24: 00000000000000c0
[   29.313277] x23: 0000000000000000 x22: ffff8000125b3378 x21: 0000000000000000
[   29.313288] x20: ffff00097ef383c0 x19: ffff00080090cb40 x18: 0000000000000010
[   29.313299] x17: 6e6e75722e677661 x16: 3e2d71725f736663 x15: 207c7c206776615f
[[0;32m  OK  [0m] Started udev [   29.341880] x14: 6c6974752e677661
x13: 6776615f656c6261 x12: 6e6e75722e677661
Coldplug all Devices.[   29.351892] x11: ffff8000126419b0 x10:
ffff800012629970 x9 : ffff800010111bec

[   29.360858] x8 : 0000000000017fe8 x7 : c0000000ffffefff x6 : 0000000000000001
[   29.368171] x5 : 0000000000000001 x4 : 0000000000000000 x3 : 0000000000000027
[   29.375324] x2 : 0000000000000023 x1 : 0000000000000000 x0 : 0000000000000000
[   29.382477] Call trace:
[   29.384923]  update_blocked_averages+0x628/0x660
[   29.389548]  newidle_balance+0x208/0x478
[   29.393477]  pick_next_task_fair+0x58/0x3b8
[   29.397666]  __schedule+0x1c4/0x1250
[   29.401249]  schedule+0x4c/0x100
[   29.404481]  worker_thread+0xc0/0x428
[   29.408147]  kthread+0x140/0x158
[   29.411380]  ret_from_fork+0x10/0x18
[   29.414960] ---[ end trace 8349fb64d5c118de ]---

Full test log,
https://lkft.validation.linaro.org/scheduler/job/2935085#L1120

metadata:
  git branch: master
  git repo: https://gitlab.com/Linaro/lkft/mirrors/next/linux-next
  git describe: next-20210621
  kernel-config: https://builds.tuxbuild.com/1uG71M0P29j62n5g5DXGExv8HJi/config

Steps to reproduce:
--------------------------
Boot arm64 kernel from this build on Juno-r2 and will get warning.

Image:
     https://builds.tuxbuild.com/1uG71M0P29j62n5g5DXGExv8HJi/Image.gz
vmlinux:
     https://builds.tuxbuild.com/1uG71M0P29j62n5g5DXGExv8HJi/vmlinux.xz
System.map:
     https://builds.tuxbuild.com/1uG71M0P29j62n5g5DXGExv8HJi/System.map

Few more log on x86:
https://qa-reports.linaro.org/lkft/linux-next-master/build/next-20210621/testrun/4955196/suite/linux-log-parser/test/check-kernel-exception-2934648/log

https://lkft.validation.linaro.org/scheduler/job/2934648#L1170

--
Linaro LKFT
https://lkft.linaro.org